Robert S. Mueller III, the special counsel investigating Russia’s election interference, has at least four dozen questions on an exhaustive array of subjects he wants to ask President Trump to learn more about his ties to Russia and determine whether he obstructed the inquiry itself, according to a list of the questions obtained by The New York Times. The questions provide the most detailed look yet inside Mr. Mueller’s investigation, which has been shrouded in secrecy since he was appointed nearly a year ago. The majority relate to possible obstruction of justice, demonstrating how an investigation into Russia’s election meddling grew to include an examination of the president’s conduct in office.